The invention pertains to an optical scanning device, in particular, for steering angle sensors. Scanning devices of this type contain a code carrier with toothed segments distributed over its length or periphery. These segments are irradiated by a radiation transmitter arranged in front of the toothed segments, and the radiation which passes through the intermediate spaces between the segments is measured with a receiver arranged behind the toothed segments.
It is frequently desired that the output signal of the receiver have a certain ratio between pulses and interpulse periods, e.g., a ratio of 1:1. This can only be achieved by utilizing a pulse shaper. A pulse shaper converts the output signals of a receiving photodiode into square-wave signals at the output of the receiver. In order to achieve a certain ratio between the pulses and the interpulse periods at the output, the transmission voltage can be changed such that the radiation level is reduced and a chronological shift of the response threshold of the converter is attained on the reception side. Another option consists of changing the response threshold on the reception side such that the beginning and the end of the respective output pulses can be controlled. However, both of the aforementioned measures are expensive and require a complicated control arrangement.